﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.Data;
using System.Collections;
using System.ComponentModel;
using System.Text.RegularExpressions;

namespace CP.Utility
{
    public static class DataTableExtensions
    {
        /// <summary>
        /// 转化一个DataTable
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="list"></param>
        /// <returns></returns>
        public static DataTable ToDataTable<T>(this IEnumerable<T> list)
        {
            //创建属性的集合
            List<PropertyInfo> pList = new List<PropertyInfo>();
            //获得反射的入口
            Type type = typeof(T);
            DataTable dt = new DataTable();
            //把所有的public属性加入到集合 并添加DataTable的列
            Array.ForEach<PropertyInfo>(type.GetProperties(),
                p =>
                {
                    pList.Add(p);
                    dt.Columns.Add(p.Name,
                        Nullable.GetUnderlyingType(p.PropertyType) ?? p.PropertyType);
                });
            foreach (var item in list)
            {
                //创建一个DataRow实例
                DataRow row = dt.NewRow();
                //给row 赋值
                pList.ForEach(p => row[p.Name] = p.GetValue(item, null));
                //加入到DataTable
                dt.Rows.Add(row);
            }
            return dt;
        }

        /// <summary>
        /// DataTable 转换为List 集合
        /// </summary>
        /// <typeparam name="TResult">类型</typeparam>
        /// <param name="dt">DataTable</param>
        /// <returns></returns>
        public static List<T> ToList<T>(this DataTable dt) where T : class, new()
        {
            //创建一个属性的列表
            List<PropertyInfo> prlist = new List<PropertyInfo>();
            //获取TResult的类型实例  反射的入口
            Type t = typeof(T);
            //获得TResult 的所有的Public 属性 并找出TResult属性和DataTable的列名称相同的属性(PropertyInfo) 并加入到属性列表 
            Array.ForEach<PropertyInfo>(t.GetProperties(), p => { if (dt.Columns.IndexOf(p.Name) != -1) prlist.Add(p); });
            //创建返回的集合
            List<T> oblist = new List<T>();

            foreach (DataRow row in dt.Rows)
            {
                //创建TResult的实例
                T ob = new T();
                //找到对应的数据  并赋值
                prlist.ForEach(
                    property =>
                    {
                        object value = row[property.Name];
                        object new_value = null;
                        Type ptype = Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType;
                        if (value == DBNull.Value)
                        {
                            if (ptype == typeof(int) ||
                                        ptype == typeof(Int32) ||
                                        ptype == typeof(decimal) ||
                                        ptype == typeof(float) ||
                                        ptype == typeof(double)

                                        )
                                value = 0;
                        }
                        if (ptype == value.GetType())
                            new_value = value;
                        else if (ptype == typeof(bool))
                            new_value = value == DBNull.Value ? false : (value.ToString() == "0" ? false : true);
                        else if (ptype == typeof(DateTime))
                            new_value = DBNull.Value;
                        else
                            new_value = TypeDescriptor.GetConverter(ptype).ConvertFrom(value.ToString());

                        if (new_value.GetType() == typeof(string) && new_value.ToString() == " ")
                            new_value = "";
                        if (new_value.GetType() == typeof(decimal) && (decimal)new_value != 0m && new_value.ToString().IndexOf(".") > 0)
                        {
                            string str_new_value = new_value.ToString();
                            str_new_value = Regex.Replace(str_new_value, "0+$", "");
                            new_value = decimal.Parse(str_new_value);
                        }

                        property.SetValue(ob, new_value == DBNull.Value ? null : new_value, null);

                    });

                //放入到返回的集合中.
                oblist.Add(ob);
            }
            return oblist;
        }

        public static List<object> ToList(this DataTable dt, Type type)
        {
            //创建一个属性的列表
            List<PropertyInfo> prlist = new List<PropertyInfo>();
            //获取TResult的类型实例  反射的入口

            //获得TResult 的所有的Public 属性 并找出TResult属性和DataTable的列名称相同的属性(PropertyInfo) 并加入到属性列表 
            Array.ForEach<PropertyInfo>(type.GetProperties(), p => { if (dt.Columns.IndexOf(p.Name) != -1) prlist.Add(p); });
            //创建返回的集合
            List<object> oblist = new List<object>();

            foreach (DataRow row in dt.Rows)
            {
                //创建TResult的实例
                object ob = Activator.CreateInstance(type);
                //找到对应的数据  并赋值
                prlist.ForEach(
                    property =>
                    {
                        object value = row[property.Name];
                        object new_value = null;
                        Type ptype = Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType;
                        if (value == DBNull.Value)
                        {
                            if (ptype == typeof(int) ||
                                        ptype == typeof(Int32) ||
                                        ptype == typeof(decimal) ||
                                        ptype == typeof(float) ||
                                        ptype == typeof(double)

                                        )
                                value = 0;
                        }
                        if (ptype == value.GetType())
                            new_value = value;
                        else if (ptype == typeof(bool))
                            new_value = value == DBNull.Value ? false : (value.ToString() == "0" ? false : true);
                        else if (ptype == typeof(DateTime))
                            new_value = DBNull.Value;
                        else
                            new_value = TypeDescriptor.GetConverter(ptype).ConvertFrom(value.ToString());

                        if (new_value.GetType() == typeof(string) && new_value.ToString() == " ")
                            new_value = "";
                        if (new_value.GetType() == typeof(decimal) && (decimal)new_value != 0m && new_value.ToString().IndexOf(".") > 0)
                        {
                            string str_new_value = new_value.ToString();
                            str_new_value = Regex.Replace(str_new_value, "0+$", "");
                            new_value = decimal.Parse(str_new_value);
                        }

                        property.SetValue(ob, new_value == DBNull.Value ? null : new_value, null);

                    });

                //放入到返回的集合中.
                oblist.Add(ob);
            }
            return oblist;
        }

        /// <summary>
        /// 将集合类转换成DataTable
        /// </summary>
        /// <param name="list">集合</param>
        /// <returns></returns>
        public static DataTable ToDataTableTow(this IList list)
        {
            DataTable result = new DataTable();
            if (list.Count > 0)
            {
                PropertyInfo[] propertys = list[0].GetType().GetProperties();
                foreach (PropertyInfo pi in propertys)
                {
                    result.Columns.Add(pi.Name, pi.PropertyType);
                }

                for (int i = 0; i < list.Count; i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in propertys)
                    {
                        object obj = pi.GetValue(list[i], null);
                        tempList.Add(obj);
                    }
                    object[] array = tempList.ToArray();
                    result.LoadDataRow(array, true);
                }
            }
            return result;
        }

        /// <summary>
        /// 将泛型集合类转换成DataTable
        /// </summary>
        /// <typeparam name="T">集合项类型</typeparam>
        /// <param name="list">集合</param>
        /// <returns>数据集(表)</returns>
        public static DataTable ToDataTable<T>(this IList<T> list)
        {
            return ToDataTable<T>(list, null);
        }

        /// <summary>
        /// 将泛型集合类转换成DataTable
        /// </summary>
        /// <typeparam name="T">集合项类型</typeparam>
        /// <param name="list">集合</param>
        /// <param name="propertyName">需要返回的列的列名</param>
        /// <returns>数据集(表)</returns>
        public static DataTable ToDataTable<T>(this IList<T> list, params string[] propertyName)
        {
            List<string> propertyNameList = new List<string>();
            if (propertyName != null)
                propertyNameList.AddRange(propertyName);

            DataTable result = new DataTable();
            if (list.Count > 0)
            {
                PropertyInfo[] propertys = list[0].GetType().GetProperties();
                foreach (PropertyInfo pi in propertys)
                {
                    if (propertyNameList.Count == 0)
                    {
                        result.Columns.Add(pi.Name, pi.PropertyType);
                    }
                    else
                    {
                        if (propertyNameList.Contains(pi.Name))
                            result.Columns.Add(pi.Name, pi.PropertyType);
                    }
                }

                for (int i = 0; i < list.Count; i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in propertys)
                    {
                        if (propertyNameList.Count == 0)
                        {
                            object obj = pi.GetValue(list[i], null);
                            tempList.Add(obj);
                        }
                        else
                        {
                            if (propertyNameList.Contains(pi.Name))
                            {
                                object obj = pi.GetValue(list[i], null);
                                tempList.Add(obj);
                            }
                        }
                    }
                    object[] array = tempList.ToArray();
                    result.LoadDataRow(array, true);
                }
            }
            return result;
        }

        public static DataTable ToDataTable(this IList list)
        {
            return ToDataTable(list, null);
        }

        public static DataTable ToDataTable(this IList list, params string[] propertyName)
        {
            List<string> propertyNameList = new List<string>();
            if (propertyName != null)
                propertyNameList.AddRange(propertyName);

            DataTable result = new DataTable();
            if (list.Count> 0)
            {
                PropertyInfo[] propertys = list[0].GetType().GetProperties();
                foreach (PropertyInfo pi in propertys)
                {
                    if (propertyNameList.Count == 0)
                    {
                        result.Columns.Add(pi.Name, pi.PropertyType);
                    }
                    else
                    {
                        if (propertyNameList.Contains(pi.Name))
                            result.Columns.Add(pi.Name, pi.PropertyType);
                    }
                }

                for (int i = 0; i < list.Count; i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in propertys)
                    {
                        if (propertyNameList.Count == 0)
                        {
                            object obj = pi.GetValue(list[i], null);
                            tempList.Add(obj);
                        }
                        else
                        {
                            if (propertyNameList.Contains(pi.Name))
                            {
                                object obj = pi.GetValue(list[i], null);
                                tempList.Add(obj);
                            }
                        }
                    }
                    object[] array = tempList.ToArray();
                    result.LoadDataRow(array, true);
                }
            }
            return result;
        }
    }
}
